Dual DVI Ports causing Sound Crackle

After recently upgrading my graphics card to an Asus EN9600GT I ran into the infamous problem of sound crackling. Through numerous trial and errors, I finally found out two things;

A) When both of my DVI outputs on the graphics card are plugged in, the sound will crackle. This is even if the second monitor is not turned on for extended desktop.
B) When only my main monitor is plugged in, the sound does not crackle.

I'm thinking this may be due to a lack of power to the card. My motherboard is only 16x, not fully PCI 2.0 complient, yet it shouldn't have such a significant problem on it's end.